This invention relates to a portable timber felling device for controlled felling of a tree with safety.
Pertinent prior art includes the following U.S. Patents: Evenson No. 2,657,904; Evenson No. 2,690,323 and Thiermann No. 3,773,292.
In certain prior art devices, a hydraulic wedge member was inserted into a kerf in a tree for felling. The wedge member, besides being unduly cumbersome, had the distinct disadvantage of having the hydraulic valves and the manual levers to operate the same located on the wedge, which placed the operator in a dangerous position. In addition, a second person was necessary to operate a chain saw engine which drove a hydraulic pump member connected between a reservoir and the wedge. The reservoir and pump were often heavy and bulky so that a truck or a similar vehicle was required to carry them to the felling site. This factor precluded such a felling device being used on steep slopes or other terrain inaccessible to a motor vehicle.
In other prior art devices the valves and manual controls thereto were located adjacent the hydraulic pump member instead of being on the wedge member. However, the operators were still close enough to the felled tree when operating the controls to be hit by flying debris. Moreover, these wedge members developed into a rather complicated structure which offered negligible control over the direction in which the tree might fall. Inaccurate felling of a tree often resulted in increased breakage and lower lumber yields especially on steep hillsides as well as damage to nearby timber.